Connected: An Internet Encyclopedia
RFC 1812 - 5.3.11 Controls on Forwarding

Top: Connected: An Internet Encyclopedia
Up: Requests For Comments
Up: RFC 1812
Up: 5. INTERNET LAYER - FORWARDING
Up: 5.3 SPECIFIC ISSUES
Prev: 5.3.10 Multicast Routing
Next: 5.3.12 State Changes

### 5.3.11 Controls on Forwarding

For each physical interface, a router SHOULD have a configuration option that specifies whether forwarding is enabled on that interface. When forwarding on an interface is disabled, the router:

- MUST silently discard any packets which are received on that interface but are not addressed to the router

- MUST NOT send packets out that interface, except for datagrams originated by the router

- MUST NOT announce via any routing protocols the availability of paths through the interface

DISCUSSION

  This feature allows the network manager to essentially turn off an interface but leaves it accessible for network management.

  Ideally, this control would apply to logical rather than physical interfaces. It cannot, because there is no known way for a router to determine which logical interface a packet arrived absent a one-to-one correspondence between logical and physical interfaces.

Next: 5.3.12 State Changes

Connected: An Internet Encyclopedia
RFC 1812 - 5.3.11 Controls on Forwarding